public class OpenPGPCFBBlockCipher extends java.lang.Object implements BlockCipher
For further info see RFC 2440.
Modifier and Type | Field and Description |
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private int |
blockSize |
private BlockCipher |
cipher |
private int |
count |
private boolean |
forEncryption |
private byte[] |
FR |
private byte[] |
FRE |
private byte[] |
IV |
Constructor and Description |
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OpenPGPCFBBlockCipher(BlockCipher cipher)
Basic constructor.
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Modifier and Type | Method and Description |
---|---|
private int |
decryptBlock(byte[] in,
int inOff,
byte[] out,
int outOff)
Do the appropriate processing for CFB IV mode decryption.
|
private int |
encryptBlock(byte[] in,
int inOff,
byte[] out,
int outOff)
Do the appropriate processing for CFB IV mode encryption.
|
private byte |
encryptByte(byte data,
int blockOff)
Encrypt one byte of data according to CFB mode.
|
java.lang.String |
getAlgorithmName()
return the algorithm name and mode.
|
int |
getBlockSize()
return the block size we are operating at.
|
BlockCipher |
getUnderlyingCipher()
return the underlying block cipher that we are wrapping.
|
void |
init(boolean forEncryption,
CipherParameters params)
Initialise the cipher and, possibly, the initialisation vector (IV).
|
int |
processBlock(byte[] in,
int inOff,
byte[] out,
int outOff)
Process one block of input from the array in and write it to
the out array.
|
void |
reset()
reset the chaining vector back to the IV and reset the underlying
cipher.
|
private byte[] IV
private byte[] FR
private byte[] FRE
private BlockCipher cipher
private int count
private int blockSize
private boolean forEncryption
public OpenPGPCFBBlockCipher(BlockCipher cipher)
cipher
- the block cipher to be used as the basis of the
feedback mode.public BlockCipher getUnderlyingCipher()
public java.lang.String getAlgorithmName()
getAlgorithmName
in interface BlockCipher
public int getBlockSize()
getBlockSize
in interface BlockCipher
public int processBlock(byte[] in, int inOff, byte[] out, int outOff) throws DataLengthException, java.lang.IllegalStateException
processBlock
in interface BlockCipher
in
- the array containing the input data.inOff
- offset into the in array the data starts at.out
- the array the output data will be copied into.outOff
- the offset into the out array the output will start at.DataLengthException
- if there isn't enough data in in, or
space in out.java.lang.IllegalStateException
- if the cipher isn't initialised.public void reset()
reset
in interface BlockCipher
public void init(boolean forEncryption, CipherParameters params) throws java.lang.IllegalArgumentException
init
in interface BlockCipher
forEncryption
- if true the cipher is initialised for
encryption, if false for decryption.params
- the key and other data required by the cipher.java.lang.IllegalArgumentException
- if the params argument is
inappropriate.private byte encryptByte(byte data, int blockOff)
data
- the byte to encryptblockOff
- offset in the current blockprivate int encryptBlock(byte[] in, int inOff, byte[] out, int outOff) throws DataLengthException, java.lang.IllegalStateException
in
- the array containing the data to be encrypted.inOff
- offset into the in array the data starts at.out
- the array the encrypted data will be copied into.outOff
- the offset into the out array the output will start at.DataLengthException
- if there isn't enough data in in, or
space in out.java.lang.IllegalStateException
- if the cipher isn't initialised.private int decryptBlock(byte[] in, int inOff, byte[] out, int outOff) throws DataLengthException, java.lang.IllegalStateException
in
- the array containing the data to be decrypted.inOff
- offset into the in array the data starts at.out
- the array the encrypted data will be copied into.outOff
- the offset into the out array the output will start at.DataLengthException
- if there isn't enough data in in, or
space in out.java.lang.IllegalStateException
- if the cipher isn't initialised.